Histology and Embryology

Question 1

What is the epithelium of the oral cavity, oropharynx, laryngopharynx and buccal surfaces?

Answer 1

Non-keratinised stratified squamous epithelium

Question 2

What are the only parts of the mouth to be keratinised?

Answer 2

Gingivae (gums) and hard palate

Question 3

What is the epithelium of the nasal cavity and nasopharynx?

Answer 3

Respiratory epithelium

Question 4

Describe the epithelium of the anterior 2/3rds of the tongue?

Answer 4

Stratified squamous epithelium- thin on ventral surface and thick with papillae on dorsal surface

Question 5

Describe the epithelium of the posterior 1/3rd of the tongue?

Answer 5

Smooth stratified epithelium

Question 6

What is the difference between serosa and adventitia?

Answer 6

If the tissue is embedded in another tissue or pegged down to something else, it is adventitia

Question 7

What is the epithelium in the oesophagus?

Answer 7

Non-keratinised stratified squamous epithelium

Question 8

What different types of muscle are found and where in the oesophagus?

Answer 8

Upper 1/3rd- skeletal
Middle 1/3rd- transition
Lower 1/3rd- smooth

Question 9

What is all the muscle of the oesophagus innervated by?

Answer 9

Vagus nerve

Question 10

Where are the only places in the GI tract that submucosal glands can be found?

Answer 10

Oesophagus and duodenum

Question 11

Where is the first sudden change of GI epithelium, what is this change?

Answer 11

At the gastro-oesophageal junction: stratified squamous epithelium to columnar epithelia

Question 12

What epithelial layer are the gastric pits which make gastric glands in the stomach found?

Answer 12

Muscularis mucosa

Question 13

What type of cells line the gastric pits and can also be found on the surface?

Answer 13

Surface mucous cells

Question 14

What does the isthmus of the gastric pits contain?

Answer 14

Stem cells, parietal/oxyntic cells

Question 15

What does the neck of the gastric pit contain?

Answer 15

Mucous and stem cells

Question 16

What do chief cells give rise to?

Answer 16

Pepsin

Question 17

What does the muscularis externa contain only in the stomach?

Answer 17

An extra layer of oblique smooth muscle

Question 18

What are crypts of Lieberkuhn?

Answer 18

Villi with pits drilling downwards found in the small intestine

Question 19

Where are the villi on the small intestine found?

Answer 19

On the plicae circularis

Question 20

What part of the small intestine has the largest villi?

Answer 20

Jejunum

Question 21

Where are the Peyer’s patches found in the ileum?

Answer 21

Submucosa and sometimes lamina propria

Question 22

What are enterocytes and what are some of their features?

Answer 22

Main absorptive cell, tall, columnar and with brush border

Question 23

What do goblet cells produce?

Answer 23

Mucin

Question 24

What do Paneth cells do?

Answer 24

Involved in defence

Question 25

What are cells that produce hormones that control secretion and motility?

Answer 25

Enteroendocrine

Question 26

What do stem cells do?

Answer 26

Replenish the epithelium

Question 27

What parts of epithelium do the plicae have?

Answer 27

Mucosa and submucosa

Question 28

What are the relative sizes of the two types of muscle in the ileum? What is the exception to this?

Answer 28

Circular muscle is very thick and longitudinal is very thin- the exception is when the longitudinal muscle is gathered into bands at the teniae coli

Question 29

What are the principle cell types in the large intestine?

Answer 29

Absorptive and goblet

Question 30

What is the epithelia of the anal canal?

Answer 30

Stratified squamous- becoming keratinised as it gets nearer the outside world

Question 31

When is the gut tube formed?

Answer 31

When the embryo folds

Question 32

What embryological part forms the gut tube?

Answer 32

Lateral aspects of the endoderm meeting

Question 33

What embryological part forms the body wall?

Answer 33

Mesoderm

Question 34

What areas of the GI tract are endoderm derived?

Answer 34

Epithelia of mucosa and associated ducts and glands

Question 35

What areas of the GI tract are visceral mesoderm derived?

Answer 35

Lamina propria, muscularis mucosa and externa, connective tissue

Question 36

What are ventral mesenteries of the GI tract?

Answer 36

Lesser omentum and falciform ligaments

Question 37

What are dorsal mesenteries of the GI tract?

Answer 37

Mesoduodenum and mesocolon, superior mesenteric artery

Question 38

Where do most mesenteries attach?

Answer 38

Dorsal border

Question 39

What are ventral mesenteries derived from?

Answer 39

Septum transversum

Question 40

When is the oesophagus distinguishable?

Answer 40

Week 4

Question 41

When does the circular muscle develop?

Answer 41

Week 5

Question 42

When does the longitudinal muscle develop?

Answer 42

Week 8

Question 43

What do the lesser omentum and falciform ligaments form?

Answer 43

Ventral mesentery

Question 44

Where are parts 1 and 2 of the duodenum derived from?

Answer 44

Caudal part of foregut

Question 45

Where are parts 3 and 4 of the duodenum derived from?

Answer 45

Cranial part of midgut

Question 46

What grows into the mesoderm of the septum transversum?

Answer 46

Liver bud

Question 47

Where do the liver cells and lining of the biliary tree come from?

Answer 47

Endoderm

Question 48

Is the pancreas always retroperitoneal?

Answer 48

No it is intraperitoneal during development

Question 49

What is it known as when a mass of pancreatic tissue forms around the duodenum, causing stenosis?

Answer 49

Annular pancreas

Question 50

Where is the spleen derived from and when does it form?

Answer 50

Mesoderm derived in week 5

Question 51

When does the spleen develop into a lymphoid organ?

Answer 51

15-18

Question 52

What connects the midgut to the yolk sac?

Answer 52

Vitelline duct

Question 53

What is a vitelline fistula?

Answer 53

Open connection from the small intestine to the outside world

Question 54

When does recanalization of the gut lumen occur?

Answer 54

Week 9